These degrees are a measure of how much effort it takes for psychologists or caretakers to conform to their vision of healthy behavior. That vision is heavily biased towards conformity, unobtrusiveness, and lack of complaint. This means that it may be healthier for you to live at 2 rather than attempt to return to 1.

It is common for autistic people's "severity" to increase when they learn to stand up for themselves and take the space they need. Eventually you may gain the experience to know how to that space in a way that doesn't demand quite as much effort from others, but that's a matter of continuing in the same direction of personal growth and development, not a return to your old state.

It is also common for autistic people's "severity" to increase when they don't learn to stand up for themselves, and the cumulative stress of trying to contort themselves to other people's expectations takes its toll on their mind and body. If your symptoms get worse while trying to conform, trying to conform harder will only make things worse.

Some autistic people do manage to 'solve' their lives and have their "severity" decrease without standing up for themselves, for example by finding a partner or institution (military, religious, corporate, etc.) who can control their lives for them in a way that is stable. This typically involves systematic emotional abuse or neglect because someone else trying to manage your emotions properly would have to do a high "severity" amount of work.

And some manage to stand up for themselves in a way that doesn't get medicalized, but that doesn't sound like an option for you.

Those classifications don't mean anything except to gatekeep who can get help and who has to go without. There is no "degree" or "severity" of autism. It's all about how easy it is for the person to mask and fit into neurotypical society. It's not a disease, it's a disability. And it's only a disability because a majority of society refuses to accommodate us. Just like many places still don't have ramps on sidewalks and stairs to accommodate physically disabled people and allow them to actively participate in society.

Anyway, my point is, be yourself. You aren't broken and you definitely aren't more broken because of some test that's solely designed to see how likely it is you'll be able to to fit into society without accommodation. Surround yourself with people who are willing to accommodate your needs instead and do what needs to be done to survive. Don't waste time on people who won't accommodate you unless it's for survival.

There is a remote mountain in China¹. The old master lives atop it. She is a mechanical engineer who designs trains. Study under her. Learn everything she has to teach. Only then will you achieve the third level.

¹actually Tibet, but she's from hong Kong so, like, it doesn't matter for these purposes.

start grinding low-level mooks in the forest area, that should give you enough XP to level up

I don't know your situation, so this may not apply.

https://www.medicalnewstoday.com/articles/autism-and-ptsd